Relocating Z80 programs one bit at a time
PRL lets Z80 code load on any suitable 256-byte boundary, using an ordinary assembler and a tiny relocation routine. Bringing CP/M to the TEC-1G led me to this decades-old solution.
Tag: cpm - 2026
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Atom 0.3.6: less guesswork
Atom 0.3.6 reports clearer errors at the source lines that need fixing. Examples show missing names, values that do not fit and short jumps that cannot reach their destinations.
Atom 0.3.5 for CP/M
With Atom 0.3.5 you can write, assemble and run Z80 programs on a CP/M machine without leaving it. Try it in Triptych with an editor and a commented example or put it on your own system.
Building a heap out of slabs
Skate divides its small heap into 256-byte pages. Pairs, bindings, closures, strings and vectors can then share the available memory without fixed reservations for each type.
Taking out the garbage
Skate reclaims list pairs that a running program can no longer reach. Its collector traces from live roots, keeps reachable pairs and returns the rest to the free list.
Room to run
Skate brings compiled Scheme to Z80/CP/M. Providing automatic memory management on a small machine means balancing runtime size, data capacity and processing time.
Scheme within limits
Skate’s design balances useful Scheme features against the memory and processing limits of Z80/CP/M. Some features remain central; others sit outside the scope of the first version.
A minimum viable Scheme
I’m building Skate, a Scheme compiler for the Z80 running CP/M. Examples from Structure and Interpretation of Computer Programs provide a test of how much we can retain while leaving enough memory to run useful programs.
Starting Skate
I’m building Skate, a Scheme compiler for Z80/CP/M. I’ll release the implementation in stages and explore how to make its expressive style of programming practical on a small machine.